Commit 20936cd1 authored by Fuad Tabba's avatar Fuad Tabba Committed by Oliver Upton
Browse files

KVM: arm64: Handle FFA_FEATURES call from the host 



Filter out advertising unsupported features, and only advertise
features and properties that are supported by the hypervisor proxy.

Signed-off-by: default avatarFuad Tabba <tabba@google.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230523101828.7328-10-will@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 634d90cf

arch/arm64/kvm/hyp/nvhe/ffa.c

+41 −4
Original line number Diff line number Diff line
@@ -64,15 +64,21 @@ static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno) 
	};

}



static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret)

static void ffa_to_smccc_res_prop(struct arm_smccc_res *res, int ret, u64 prop)

{

	if (ret == FFA_RET_SUCCESS) {

		*res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS };

		*res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS,

						.a2 = prop };

	} else {

		ffa_to_smccc_error(res, ret);

	}

}



static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret)

{

	ffa_to_smccc_res_prop(res, ret, 0);

}



static void ffa_set_retval(struct kvm_cpu_context *ctxt,

			   struct arm_smccc_res *res)

{
@@ -484,14 +490,41 @@ static bool ffa_call_supported(u64 func_id) 
	case FFA_RXTX_MAP:

	case FFA_MEM_DONATE:

	case FFA_MEM_RETRIEVE_REQ:

	/* Don't advertise any features just yet */

	case FFA_FEATURES:

		return false;

	}



	return true;

}



static bool do_ffa_features(struct arm_smccc_res *res,

			    struct kvm_cpu_context *ctxt)

{

	DECLARE_REG(u32, id, ctxt, 1);

	u64 prop = 0;

	int ret = 0;



	if (!ffa_call_supported(id)) {

		ret = FFA_RET_NOT_SUPPORTED;

		goto out_handled;

	}



	switch (id) {

	case FFA_MEM_SHARE:

	case FFA_FN64_MEM_SHARE:

	case FFA_MEM_LEND:

	case FFA_FN64_MEM_LEND:

		ret = FFA_RET_SUCCESS;

		prop = 0; /* No support for dynamic buffers */

		goto out_handled;

	default:

		return false;

	}



out_handled:

	ffa_to_smccc_res_prop(res, ret, prop);

	return true;

}



bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)

{

	DECLARE_REG(u64, func_id, host_ctxt, 0);
@@ -514,6 +547,10 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt) 
		return false;



	switch (func_id) {

	case FFA_FEATURES:

		if (!do_ffa_features(&res, host_ctxt))

			return false;

		goto out_handled;

	/* Memory management */

	case FFA_FN64_RXTX_MAP:

		do_ffa_rxtx_map(&res, host_ctxt);